Relay



SePt- 22, 1953 J. T. l.. BROWN ET AL RELAY Filed Nov. 5, 1948 TUV /N l/EN 7' ORS I J TL BROWN W5-ELLWO BV 0 Patented Sept. 22, 1953 RELAY JohnT. L. Brown, Short Hills, N. J., and Walter B. Ellwood, New York, N. Y.,assignors to Bell Telephone Laboratories, Incorporated, New York, N. Y.,a corporation of New York Application November 5, 1948, Serial No.58,522

(Cl. G-87) 2 Claims.

This invention relates to circuit controlling devices and morespecifically to relays of the type known as dry reed relays comprising avessel with enclosed contacts and a magnetic flux source external to thesaid vessel.

An object of the invention is to reduce the cost and increase theutility and durability of such devices as well as the reliability ofoperation.

Another object of the invention is to permit large scale manufacture ofthis type relay and at the same time maintaining a high degree ofaccuracy, uniformity, and speed of operation of said relay.

A further object of the invention is the improvement of dry reed relaysgenerally.

The prior art discloses many relays of the dry reed type comprising avessel with enclosed spring contacts and a magnetic iiux source externalto said vessel. Reference is made to United States patents, Dorn andHandke, 1,836,654, issued December 5, 1931 and Ellwood, 2,289,830,issued July 14, 1942.

The application to practical use of the relays disclosed in the priorart has been impeded considerably due to the slow and costly methods ofmanufacturing them with suliicient accuracy, uniformity, and speed. Muchof this diiiculty arises from the problem of obtaining the correctspatial relationship between the electrodes within the vessel. In thepresent invention a new structure for such relays is presented inaccordance with which such relays can be manufactured more expeditiouslywith the degree of accuracy and uniformity necessary for their largescale commercial application. One of the contacts is a magnetic springwire surrounded by a flux conducting cylinder, one end of said springwire being secured in one end of the vessel which in the preferredembodiment of the invention is a glass tube, the other end of saidspring wire electrode being free and also being the contact end. Theother electrode is a magnetic metal tube, one end of which is secured inthe other end of the glass tube, and the other end of said metal tubebeing cut so as to introduce an unsymrnetrical distribution of magneticflux about the Wire. A step cut in the end of the tube or a diagonal cutacross the end will attain this result.

The aforementioned spring wire, being of a smallerl diameter than theorice of the metal tube, extends a short distance into the metal tube.Excitation of the external magnetic means causes the magnetic springwire electrode to make contact with the inside of the magnetic metaltube electrode. The offset cutting of the free end of the metal tubeinsures a greater flux concentration on one side of the spring wireelectrode than on the other. In addition the use of a metal tube as oneof the electrodes provides for ease of manufacture. As mentioned supraone of the more difficult problems in the manufacture of this type relayis obtaining the proper spatial relationship between the electrodes. Aspring jig can be inserted through the orifice of the metal tubeelectrode to grip the spring wire electrode and hold it in the desiredposition While the sealing processes on the glass tubing is carried out.Since the electrodes are secured in said seals, the spring Wireelectrode will be permanently positioned when the sealingr operation iscompleted. The jig can 'then be removed from the metal tube leaving therelay ready for evacuation and reiilling with a noncorrosive gas. Thejig should be of a type to Sulliciently center the wire in the tube withacceptable tolerances in diameters of wire and tube.

In the manufacturing of other relays of this type, highly skilledtechnicians are required to properly construct said other relays,whereas in the present invention relatively unskilled workers can beemployed for manufacturing said invention.

Furthermore a multiple position rotary machine similar to what is usedin the commercial production of vacuum tubes and lamps can be utilizedin the production of this relay. As a result of the above-mentionedadvantages the cost of manufacturing the relay disclosed in thisinvention is much less than the cost of manufacturing other high qualityrelays of this general type.

The invention can be more easily and fully understood from the detaileddescription given infra, read in conjunction with the drawing now to bedescribed.

The drawing shows a detailed View of the relay in which all theessential parts are shown.

The electrode containing vessel l which in the preferred embodiment ismade of glass tubing has air-tight seals 2 and 3 at either end and isfilled with a non-corrosive gas, preferably hydrogen although othergases may be used, Electrodes 4 and 5 are secured in place by the saidseals 2 and 3. Around electrode 4 is a flux conducting cylinderElectrodes 4 and 5 are composed of material capable of conducting iluxand current such as a nicke1-iron alloy. The Contact points 9 and I0 ofelectrodes 5 and 4 are infused with gold. Both of these electrodes, inthe preferred embodiment, are composed of an alloy of approximatelyfifty-one per cent nickel and fortymine per cent iron. It is to be notedhowever, that other suitable magnetic alloys may also be employed in thestead of the above-mentioned preferred material, and the contact points9 and ID may be infused with material other than gold. The sealed vessell is preferably a glass tube of high quality precision manufacture,although other type tubing may be used.

A heretofore diilicult problem in the manufacture of this type switch isthc positioning of one electrode with respect to the other. Alleviationof this problem is accomplished by having electrode 5 be a rigid metaltube with an orifice at the position of seal E. .A jig may be insertedin this orifice to grip the other electrode 4 and position it withrespect to electrode 5. Said orince is sealed by seal 6 after vessel lhas been lled with a non-corrosive gas.

Around electrode l is a cylindrical metal tube l which is composed oimagnetic material. 1t has been found that in the prior art where a metaltube such as l was not employed a considerable amount of flux was lostalong the length of the electrode with a resultant loss in thesensitivity of the electrodes to the energization oi coil 8.

The path of the i'lux begins along electrode 4 and metal tube l. A partof the flux in metal tube l flows to electrode Il at the free end ofmetal tube l. The linx path then continues along the remainingrightehand (in the drawing) end of electrode 4 and jumps the air gap toelec trede Inasmuch as the end of electrode 5 is cut off at an angle asillustrated in the drawl ing more of the flux leaving electrode 4 willflow to electrode 5 via that section of electrode 5 overlappingelectrode 4 than will flow to electrode 5 Via that section of electrode5 not overlapping electrode 4. This diilerence is of course caused bythe differences in air gaps.

The uneven distribution of iiux flowing from electrode 4 to electrode 5causes the electrode 4 to move in the direction of the greatestconcentration of ilux lines which is of course in the direction of thatpart of electrode 5 which overlaps electrode il. Electrical contactbetween the two electrodes is thus eitected. To break Contact it is onlynecessary to cle-energize coil 8 which will cause decay of the magneticiield and the contacts will then release. Coil 8 is err ternal tocontaining vessel l and is the source of the magnetic flux :field whichactuates the switch.

It is to be understood that the form of the invention, herewith shownand described, is to be taken as a preferred example of the same, andthat Various changes in the composition, shape, size and arrangement ofparts may be resorted to, without departing from the spirit of theinvention, or the scope of the subjoined claims.

What is claimed is:

l. A magnetically operated relay device comprising an elongated vitreoustube, a wire spring contact member extending through an end wall of saidtube and supported solely therein by the seal between said tube and saidmember, a hollow Contact member extending into the other end wall ofsaid tube and supported and postioned therein solely by the seal betweensaid hollow tube and said member, said hollow tube having an interioropening of adequate diameter for the insertion of a jig therethrough tohold said wire spring member intor a desired close spacing relation withrespectto said hollow member during sealing, the interior end of saidhollow member being cut oft at an angle such that one side of its endlies opposite to the end of the wire spring member for makinga contactand the other side of its end is spaced away lengthwise from said end ofthe wire spring member, and the outer end of said hollow cylindricalmember being collapsed to form an airtight seal, said wire spring memberand said hollow member consisting of magnetic material.

2. A relay in accordance with claim 1 wherein said wire spring member issurrounded for most of its length except a portion at the free interiorend thereof by a magnetic cylinder sealed into said vitreous tube andcompletely out of contact with said wire spring member throughout itslength.

JOHN T. L. BROWN. WALTER B. ELLWOOD.

References Cited in the le of this patent UNITED STATES PATENTS Number

